Acetic Acid → Ethyl 5,7-dichloro-8-methoxyquinoline-3-carboxylate

Participants

Reaction Steps

A suspension of zinc powder (0.70 g) was stirred at 20° C. in a solution of 4,5,7-trichloro-8-methoxy-quinoline-3-carboxylic acid ethyl ester 26 (364 mg, 1.09 mmol) and acetic acid (2.2 ml) in 1,4-dioxane (15 ml). After 20 minutes, ethyl acetate (20 ml) was added and the resultant mixture filtered through a pad of celite. The filtrate was washed with saturated aqueous sodium chloride solution (10 ml), dried (MgSO4), filtered, and the solvent removed under vacuum. The residue was chromatographed on flash silica (ethyl acetate/hexane, 1:9), yielding 130 mg (39%) of the title compound 27 as a white solid. 1H NMR (CDCl3, 400 MHz): δ 9.51 (d, J=2.0, 1 H), 9.15 (d, J=2.0, 1 H), 7.72 (s, 1H), 4.51 (q, J=7.2, 2 H), 4.18 (s, 3H), 1.47 (t, J=7.2, 3 H).

Provenance & Evidence